Certain cardiac rhythm or function management devices can sense intrinsic heart contractions, deliver pacing pulses to evoke responsive heart contractions, or deliver a shock to interrupt certain arrhythmias. In certain examples, this can help improve a patient's heart rhythm or can help coordinate a spatial nature of a heart contraction, either of which can improve cardiac output of blood to help meet the patient's metabolic need for such cardiac output.
Dual chamber pacing can involve pacing the right atrium (RA), followed by a right ventricular (RV) pace, which is typically delivered at the RV apex. In an example, an atrioventricular (AV) delay between an RA pace or sensed RA contraction and a scheduled following RV pace can be set to optimize ventricular filling time, which, in turn can promote better cardiac output of blood. Cardiac resynchronization therapy (CRT) can be used to synchronize or spatially coordinate RV and left ventricular (LV) contractions, such as for more efficient pumping. CRT can involve using a coronary sinus (CS) lead to position one or more electrodes near the LV. CRT can include pacing both the RV apex and the LV (e.g., via the CS lead), such as to induce a simultaneous contraction of the RV and LV. However, such a technique can require a CS lead to access the LV. Right atrium (RA) or RV His-bundle pacing can be used instead of RV and CS/LV bi-ventricular pacing.
Ortega et al. U.S. Pat. No. 7,512,440, entitled VENTRICULAR PACING, refers to a method and apparatus for treating a condition of a patient's heart, including placing a first electrode and a second electrode in a right ventricle of the heart. Borowitz et al. U.S. Patent Publication No. 2006/0064027, entitled IMPLANTABLE MEDICAL DEVICE WITH HIS-PURKINJE ACTIVITY DETECTION, refers to using an atrial lead and a ventricular lead to acquire data and processing the data to indicate electrical timing with the His-bundle.